Apparatus for mixing liquid concentrate with a diluent

ABSTRACT

Apparatus for mixing a liquid concentrate, such as a pesticide, fertilizer or the like, with a diluent, such as water under pressure, operated by the diluent pressure and which provides a constant volumetric mixing ratio irrespective of variations in diluent rate of flow or pressure thereof. It is further characterized by a reciprocating floating piston having equal and constant displacements at its opposite ends which receive and discharge liquid diluent and to which is added a metered volume of the concentrate by a reciprocating metering spool valve carried by the piston which serves as a pump, the stroke of which may be adjusted to vary the volume of the added concentrate. The stroke of the pump may also be adjusted to a position in which only diluent may be admitted for flushing concentrate from the apparatus to thereby prevent corrosion of the various internal parts of the apparatus upon completion of its use.

United States Patent [72] Inventor Ralph A. Bonetti 5970 S. Gaylord Way, Littleton, Colo. 80120 [21 Appl. No. 860,994

[22] Filed Sept. 25, 1969 [45] Patented June 29, 1971 [54] APPARATUS FOR MIXING LIQUID CONCENTRATE WITH A DILUENT 7 493,498,534 [561 References Cited UNITED sures PATENTS Re. 173,579 3/1878 Bergstrom 73/248 Primary E.raminer-Robert B. Reeves Assistant ExaminerLarry H. Martin Attorney-Sheridan, Ross & Burton ABSTRACT: Apparatus for mixing a liquid concentrate, such as a pesticide, fertilizer or the like, with a diluent, such as water under pressure, operated by the diluent pressure and which provides a constant volumetric mixing ratio irrespective of variations in diluent rate of flow or pressure thereof. It is further characterized by a reciprocating floating piston having equal and constant displacements at its opposite ends which receive and discharge liquid diluent and to which is added a metered volume of the concentrate by a reciprocating metering spool valve carried by the piston which serves as a pump, the stroke of which may be adjusted to vary the volume of the added concentrate. The stroke of the pump may also be adjusted to a position in which only diluent may be admitted for flushing concentrate from the apparatus to thereby prevent corrosion of the various internal parts of the apparatus upon completion of its use.

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sum 3 or 3 INVENTOR RALPH A. BONETT/ ATTORNEYS APPARATUS FOR MIXING LIQUID CONCENTRATIE WITH A IDKLUIENT BACKGROUND OF THE INVENTION In the art of mixing chemicals, particularly those in liquid form, it is often important that they be mixed in predetermined ratios to thus provide an end product which is the desired reactant of the chemicals or a desired dilution of same. In the horticultural art it is now common practice to package chemicals such as pesticides, fertilizers and the like, in concentrates form which must be diluted before application. If the concentrate is excessively diluted it may be ineffective for its intended purpose and if insufficiently diluted it may be harmful for its intended purpose and also result in waste of the concentrate which is often expensive compared to the diluent, such as water. In the batch process of mixing concentrates with water, exemplary of which is the mixing of a predetermined volume of the concentrate with a predetermined volume of water in a reservoir supply to later be delivered, such as by a spray nozzle, control of the ratio may be readily attained if the operator carefully measures the respective volumes. Under continuous flow conditions, however, in contradistinction to the batch process of mixing, the mixture ratio is not under such control of the operator and hence the proper ratio may be attained only if the apparatus is properly designed to effect the optimum mixture ratio. Various mixing devices have been devised for this purpose which are intended to effect optimum mixture ratios but, so far as is known, none have operated upon the general principle of the batch process under conditions of continuous flow, that is, where a relatively small batch of diluent is mixed with a proportioned amount of concentrate and the outgoing dilution flows under continuous flow conditions.

SUMMARY OF THE INVENTION While the invention may have various uses in mixing liquid chemicals, or diluting a liquid concentrate, a specific use for one type of application resides in a portable spray device or gun which carries a supply of concentrate which is diluted with water supplied by a conventional garden hose to which the spray device is attached. A floating piston reciprocates in a cylinder, the piston carrying inlet and outlet valves which are automatically reciprocated at the ends of the piston stroke to form a water motor, the alternate discharges of which communicate with the spray nozzle. The piston also carries a spooltype valve, which serves as a pump, the stroke of which may be varied by a pair of adjustable abutments adjacent the opposite ends of the cylinder. Each stroke of the spool valve sucks concentrate from the supply into chambers disposed adjacent opposite sides of the spool in a quantity greater than required for the desired dilution and upon its return stroke returns a portion to the supply, the remaining trapped portion being delivered to the diluent, this remaining portion being adjustable as desired by a pair of adjustable abutrnents which may vary the stroke of the spool valve. A suitable port, normally maintained closed by the spool during its reciprocation, may be opened by one of each of the pair of abutments to permit water, rather than concentrate, to enter the spool valve chambers and purge or flush remaining concentrate through the spray nozzle, thus cleaning some of any residual concentrate which might'cause corrosion or other damage to the various internal passages of the apparatus. Since the mixing action is volumetric, rather than dependent upon flow velocity, the mixing ratio remains constant irrespective of the pressure of the diluent.

It is, accordingly, among the objects of the invention to provide apparatus of the type referred to and operable in the manner set forth. Further objects, advantages, and salient features will become more apparent from the detailed descrip tion, the appended claims and the accompanying drawing to now be briefly described.

BRIEF DESCRIPTION OF THE DRAWING FIG. l is an isometric view of an exemplary form of the subject of the invention;

FIG. 2 is a partial bottom plan as viewed in the direction of arrow 2, FIG. 1;

FIG. 3 is a section taken substantially on line3-3, FIG. 2, a portion being broken away;

FIG. 4 is a section taken on line 4-4, FIG. 5;

FIG. 5 is a section taken on line 5-5, FIG. 3; and

FIG. 6 is a detail as viewed in the direction of arrows 6-6, FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, and first to FIGS. 11 and 2, the subject of the invention comprises, in general, a mixing chamber 10 having a cylindrical tube 112 closed at opposite ends by end walls l4, l6 and secured together by four tie bolts 18 extending between the end walls. An inlet pipe 20 is secured to end wall 14, and is provided with a conventional threaded male coupling on the end of a garden hose 24. A delivery pipeor wand 26 is secured to end plate 16, its outer end being provided with a nozzle 28 for delivering liquid in a fine divergent spray to plants or the like. A handle 30 is secured to the device so far described in any suitable manner, such as to end wall 16. A base member 32 is secured to the cylindrical tube 12 and between the end walls 14, 116 by the lower pair of tie bolts 13, which is provided, as shown in FIGS. 2 and 3, with an arcuate tapered ledge 34 which receives a tapered circular flange 36 on a container lid 38. A semicircular pin 40 is disposed in the arcuate recess of ledge 34 which engages a corresponding cutout in flange 36 for indexing it to a single mating position. A cam 42 is secured to the base by a pivot pin 44 and carries a handle 46 for swinging it between locked and unlocked positions with flange 36, a cutout 48 being provided to permit insertion and release of the container lid with the ledge and the cam. As will be apparent, handle 46 may be rotated to the dotted position in FIG. 2 so that flange 36 may be inserted on ledge 34 and in registry with indexing pin 40, whereupon cam 42 may then be rotated to the full line position, locking the lid to the base. The cam is so shaped that when it is rotated the flange is cammed toward the base and into sealing engagement with a gasket, shown as an O-ring 50 in FIG. 3. Also as best shown in FIG. 3, lid 38 is provided with rounded threads 52 of the mason jar type which receive the threaded neck of a container (not shown), a gasket 54 being provided to sealingly engage the annular end surface of the container. A flexible dip tube 56 is secured to lid 38 through which liquid concentrate in the container may be aspirated, as will subsequently be described, and a U-shaped vent tube 58 communicates the container through any suitable bleed port 60) to the atmosphere to thereby permit entry of air as the contents of the container are consumed. End walls l4, 16 each rotatably carry a mixing ratio knob 62 and wand 26 may be provided with a stopcock 64 if desired.

Referring now to FIGS. 3, 4i and 5, cylinder or tube 12 slidably receives a piston 66 which carries a inlet tube 68 and outlet tube 70 which slide in the end walls and are suitably sealed, such as by O-rings 72. The piston is sealed to the cylinder by a pair of resilient seal rings 74, illustrated as of the U-shape or chevron type. Inlet slide tube 68 communicates with inlet valve 76, through a conduit 7 8 which delivers water under pressure to annular space surrounding the valve. The valve is provided with O-rings 82 which seat against conical surfaces 83 in the piston. In the position shown in FIG. 4, communication to chamber 8 is closed and communication to chamber 66 is open. The valve is slidable in the piston and its ends abut conical springs 88 in the end walls, one of which is shown, which shift the valve upon continued movement of the piston. When this occurs, the communication to chambers 84, 86 is reversed, as will subsequently be described in further detail.

Outlet slide tube 70 communicates with outlet valve 90 through a conduit 92 and an annular space 94 surrounding the valve. The outlet valve is similar to the inlet valve, the essential difference being that the faces of the valve seats in the piston are reversed, facing outwardly rather than toward each other.

Before proceeding with the detailed description of the concentrate-mixing apparatus, the operation of the piston and its inlet and outlet valves will now be described. Briefly, this comprises, in effect, a water motor having a floating piston which reciprocates in a cylinder and forming two expansible chambers adjacent its ends, one of which is receiving liquid under pressure while the other is delivering liquid under pressure applied by one end of the piston.

More specifically, and with particular reference to FIG. 4, let it be assumed that piston 66 has been moving to the left and the left end of inlet valve 76 has abutted spring 88, as shown, and opened its left valve, communicating chamber 86 with the water supply through conduit 78. The left end of outlet valve 90 has also abutted its corresponding spring and is now closed. Water under pressure now enters chamber 86 forcing the piston to the right. Due to the differential pressure between chambers 86 and 84 the right valve of the inlet valve 76 will be maintained closed and the left valve of outlet valve 90 will be maintained closed. The right valve of outlet valve 90, however, is now open and the volume of liquid trapped in chamber 84 is discharged through port 92 and slide tube 70 (FIG. to spray nozzle 28. As will be apparent, when the piston reaches its right limit of travel, the inlet and outlet valves abut like springs 88 (not shown) in end wall 14 and operate the valves to effect return movement of the piston to the position shown in FIG. 4, the water which is now filling chamber 84 forcing the water trapped in chamber 86 through the now open left valve of outlet valve 90 and to the nozzle in the same manner first described.

Proceeding now to the detailed description of the concentrate-mixing apparatus, piston 66 also slidably carries a spool valve 96 having opposite ends which abut adjustable abutments 98 carried by end walls l4, 16, one of which is shown. Each is in the form of a stepped face cam 100, affixed to a knob 62 and which may be rotated to place a selected step in the path of the spool valve. Preferably, the knobs are suitably graduated with indicia and both are set to the same indicia which thus effects the same stroke of the spool valve on opposite sides of its central position. The spool is provided with O-rings 102 and its oppositely projecting stems I04 slide in chevron-type seals 106 which serve as one-way check valves which prevent liquid in chambers 84, 86 from entering the annular spaces surrounding the stems and permit liquid in such spaces to be delivered to chambers 84, 86 upon relative motion between the spool valve and the piston. A pair of ports 108, spaced equidistant from the midposition of the piston, communicate the spool valve with an elongated slot 110 which is in constant communication with dip tube 56. An elongated seal 112 preferably surrounds slot I10, as best shown in FIG. 6.

In the operation of the metering spool valve, and referring particularly to FIG. 3, let it be assumed that knobs 62 have been placed at the same settings and that piston 66 is about to move to the right. During the movement of the piston to the right, however, the spool valve was formally in a position to the left of that shown and at some point in the left movement of piston 66 the left stem 104 engaged an abutment 98 and by continued movement of the piston to the left the piston valve was moved to the right to the position shown. During this movement is passed across left port 108 and sucked in concentrate via left port 108, slot 110, and tube 56. The annular chamber around left stem 104 is thus now full of concentrate. Let it now be assumed that piston 66 now moves to the right, the operation of which has been previously described. At some point during the right movement of the piston the right stem 104 will abut an abutment 98 (not shown) and move the spool valve relative to the piston, that is, as the piston continues to move to the right the spool valve moves to the left. The spool valve will now return some of the concentrate trapped at its left end to the concentrate container and until it closes left port 108. After it crosses port 108, however, the remaining concentrate is forced through the left one-way valve K06 and into chamber 86. As will now be apparent the volume of water delivered to each varies according to the stroke of the spool-metering valve, controlled by the settings of knobs 62.

Upon completion ofa spraying operation it will be apparent that concentrate will remain in the metering spool valve and also diluted concentrate will remain in other portions of the device. Since the concentrate may be corrosive it is desired that means be provided for flushing the entire apparatus with water to thereby remove all concentrate from same, which means will now be described. A port 114 is disposed centrally of the piston and communicates the spool valve bore with the space surrounding the inlet valve. In all positions of knobs 62 and their abutments 98, except one, the spool valve will have insufficient stroke to uncover this port and the spool valve will operate to meter concentrate as previously described. When it is desiredto flush, however, the concentrate container is preferably removed and the knobs adjusted to effect maximum stroke of the spool valve which will now uncover port 114. Water is now delivered to the spool valve chambers, and the spool valve back flushes this water through port 114 and also through the wand as heretofore described. After a few reciprocations of the piston all remaining concentrate in the apparatus will be diluted to such minor concentration that corrosion will be obviated.

It will be appreciated that the herein apparatus also relates to a liquid-operated motor comprising a cylinder having spaced end walls; a piston slidable in the cylinder in direction toward and away from the end walls, forming a pair of variable volume chambers; a reciprocal inlet valve carried by the piston having ends adapted to abut one or the other of the end walls during reciprocation of the piston; said inlet valve being adapted to engage alternately a pair of spaced valve seats in the piston; a liquid supply port communicating with the inlet valve between said valve seats; said liquid supply port communicating with one end of a tube carried by the piston and sealingly slidable in one of the end walls, the other end of the tube communicating with a source of liquid under pressure; and a like reciprocal outlet valve and spaced valve seats carried by the piston communicating with one end of a like outlet tube carried by same and sealingly slidable in the other end wall; the construction and arrangement being such that when one chamber is being filled, the pressure therein moves the piston and discharges the liquid in the other chamber through the outlet tube, the total volume of flow through the motor being directly proportional to the number of reciprocations of the piston. When this liquid-operated motor is used with a counter, the rate or quantity of fluid flow may be measured.

In view of the foregoing, it will now be readily apparent that a unique apparatus for mixing a liquid concentrate with a liquid diluent has been illustrated and described. The apparatus of this invention provides extremely precise proportioning of the concentrate relative to the diluent under conditions which are independent of the pressure and rate of flow of either of said liquids. This is particularly advantageous when it is remembered that for mixing many liquid concentrates, such as various pesticides, the results to be obtained from using such concentrates in dilute form are predicated upon predetermined dilution ratios permitting only small variances from the desired dilution ratio. Additionally, through the use of an apparatus constructed in accordance with this invention, the user of such an apparatus need not disassemble same to ensure that the liquid concentrate has been completely purged or flushed therefrom. Further, the apparatus of this invention may be safely used for mixing and handling liquid concentrates which could cause injury if same came into contact or was exposed to the skin of the user thereof, since the user of such an apparatus never has to come into direct contact with the liquid concentrate prior to the time that same emerges in a diluted, spray form. Finally, not only is the apparatus of this invention relatively inexpensive to manufacture, but also due to the accurate proportioning achieved from the use thereof results in a reduced cost in the total amount of concentrate used and, for all practical purposes, waste of liquid concentrate is substantially eliminated.

It will be understood that certain specific structure previously described is exemplary and may be modified in the light of the concepts set forth without departing from the spirit of the invention. For example, the concentrate container may be formed with integral end walls, rather than with a removable lid 35, and be prefilled with the concentrate to minimize possibility of contact of same by the user. Also, it may be completely sealed and opened by a puncturing conduit when it is applied to the mixing apparatus so that puncturing and scaling to the apparatus occur simultaneously and prevent leakage. Conical springs 88 may also be modified by use of other resilient abutments which perform the same function and check valves 106 may be otherwise modified by use of wellknown ball-check or plate-type valves which also serve the same function as the chevron-type valves. Ports H08 which communicate with a common source of concentrate could also, if desired, communicate with two separate sources of concentrate, either by suitable sealed conduit passages or by flexible tubes. This would be of particular utility where the two concentrates are immiscible in concentrates form but become miscible when diluted. ln this modification, a mixing chamber could be provided in the discharge conduit 26 where the two diluted concentrates mix before being delivered to the spray nozzle 28.

What l claim is:

1. Apparatus for mixing a liquid concentrate with a liquid diluent under pressure comprising;

a. a first pair of diluent chambers separated by a first movable wall adapted to reciprocate and vary the volume of the chambers between predetermined limits,

b. diluent inlet and outlet valves for alternately admitting the diluent to said chambers for moving the wall, whereby one chamber and said wall form a diluent actuated motor while the other chamber and said wall provide a discharge volume,

c, a second pair of concentrate chambers separated by a second movable wall, and concentrate inlet and outlet valves for same,

d. a pair of adjustable abutments for alternately moving the second movable wall a variable desired distance dependent upon the position of the abutments,

e. means alternately communicating said second chambers with a source of the concentrate, and

f. means alternately communicating one of said second chambers with one of said first chambers,

g. the construction and arrangement being such that said second chambers alternately meter a constant-desired volume of concentrate to a predetermined volume of diluent irrespective of the pressure and rate of flow of the diluent.

2. Apparatus in accordance with claim I wherein the inlet and outlet valves are carried by the first movable wall.

3. Apparatus in accordance with claim 1 wherein the movable wall is a first piston slidable within a first cylinder.

4. Apparatus in accordance with claim 3 wherein the inlet and outlet valves are carried by the first piston.

5. Apparatus in accordance with claim 1 wherein the second movable wall is a second piston slidable within a second cylinder.

6. Apparatus in accordance with claim 5 wherein the second piston forms a concentrate inlet valve for closing com munication with a source of concentrate.

I 7. Apparatus in accordance with claim 6 wherein the stroke of the second piston is sufficient to fill a concentrate chamber with an excess of concentrate and return a portion to the source of concentratethroufih the concentrate inlet valve, further motion of the piston t ence forcing a metered volume of concentrate through the concentrate outlet valve.

8. Apparatus in accordance with claim 7 wherein the concentrate outlet valve is a check valve adapted to open when the concentrate pressure exceeds the downstream pressure of the diluent to which it is added.

9. Apparatus in accordance with claim 1 wherein said abutments are matched stepped surfaces, adapted to vary the stroke of the second movable wall in predetermined matched increments, to thereby deliver variable volumes of the concentrate in accordance with the increments to fixed volumes of the diluent, to permit varying the mixing ratio of diluent to concentrate.

10. Apparatus in accordance with claim 1 wherein the diluent is waterand the concentrate is? a horticultural composition, the apparatus being portable and including a spray nozzle for delivering the water-diluted composition to plants or the like, the water being supplied by a garden hose and the concentrate being supplied by a removable container carried by the apparatus. I

11. Apparatus in accordance with claim 10 wherein the container is disposed beneath the remaining apparatus and the second movable wall is constructed to provide suction for lifting the concentrate to the concentrate chambers.

12. Apparatus for mixing an additive liquid with a liquid diluent under pressure comprising;

a. a cylinder having spaced end walls,

b. a main piston slidable in the cylinder in directions toward and away from the end walls, forming a pair of spaced variable volume chambers,

c. a pair of reciprocable valves carried by the main piston having ends adapted to abut one or the other of the end walls, during reciprocation of the piston,

d. each valve adapted to communicate with a source of water under pressure and deliver same to one or the other of said chambers dependent upon its position relative to the main piston and an end wall,

e. a common outlet from the chambers adapted to supply liquid to a spray nozzle,

. the construction and arrangement being such that when one chamber is being filled, the pressure therein moves the piston and discharges the liquid in the other chamber to the outlet,

g. a slidable metering piston carried by the main piston having ends adapted to periodically abut adjustable abutments, each disposed adjacent an end wall to thereby adjust the length of stroke of the metering piston,

. a pair of spaced ports communicating with a source of additive liquid to be mixed with the water and across which the metering piston may slide to establish or disestablish communication with said source, and

. check valves communicating each side of the metering piston with each chamber,

j. the construction and arrangement being such that during movement of the main piston toward a cylinder end, the metering piston moves in the opposite direction a predetermined distance, depending upon the position of its adjustable abutment and returns a portion of the additive to its source until it covers one of said ports, further relative movement between the main piston and metering piston moving the latter a predetermined distance beyond the covered port and delivering a metered quantity of the additive through one of the check valves and into one of said chambers, whereby mixing occurs during filling of said one of the chambers. 

2. Apparatus in accordance with claim 1 wherein the inlet and outlet valves are carried by the first movable wall.
 3. Apparatus in accordance with claim 1 wherein the movable wall is a first piston slidable within a first cylinder.
 4. Apparatus in accordance with claim 3 wherein the inlet and outlet valves are carried by the first piston.
 5. Apparatus in accordance with claim 1 wherein the second movable wall is a second piston slidable within a second cylinder.
 6. Apparatus in accordance with claim 5 wherein the second piston forms a concentrate inlet valve for closing communication with a source of concentrate.
 7. Apparatus in accordance with claim 6 wherein the stroke of the second piston is sufficient to fill a concentrate chamber with an excess of concentrate and return a portion to the source of concentrate through the concentrate inlet valve, further motion of the piston thence forcing a metered volume of concentrate through the concentrate outlet valve.
 8. Apparatus in accordance with claim 7 wherein the concentrate outlet valve is a check valve adapted to open when the concentrate pressure exceeds the downstream pressure of the diluent to which it is added.
 9. Apparatus in accordance with claim 1 wherein said abutments are matched stepped surfaces, adapted to vary the stroke of the second movable wall in predetermined matched increments, to thereby deliver variable volumes of the concentrate in accordance with the increments to fixed volumes of the diluent, to permit varying the mixing ratio of diluent to concentrate.
 10. Apparatus in accordance with claim 1 wherein the diluent is water and the concentrate is a horticultural composition, the apparatus being portable and including a spray nozzle for delivering the water-diluted composition to plants or the like, the water being supplied by a garden hose and the concentrate being supplied by a removable container carried by the apparatus.
 11. Apparatus in accordance with claim 10 wherein the container is disposed beneath the remaining apparatus and the second movable wall is constructed to provide suction for lifting the concentrate to the concentrate chambers.
 12. Apparatus for mixing an additive liquid with a liquid diluent under pressure comprising; a. a cylinder having spaced end walls, b. a main piston slidable in the cylinder in directions toward and away from the end walls, forming a pair of spaced variable volume chambers, c. a pair of reciprocable valves carried by the main piston having ends adapted to abut one or the other of the end walls, during reciprocation of the piston, d. each valve adapted to communicate with a source of water under pressure and deliver same to one or the other of said chambers dependent upon its position relative to the main piston and an end wall, e. a common outlet from the chambers adapted to supply liquid to a spray nozzle, f. the construction and arRangement being such that when one chamber is being filled, the pressure therein moves the piston and discharges the liquid in the other chamber to the outlet, g. a slidable metering piston carried by the main piston having ends adapted to periodically abut adjustable abutments, each disposed adjacent an end wall to thereby adjust the length of stroke of the metering piston, h. a pair of spaced ports communicating with a source of additive liquid to be mixed with the water and across which the metering piston may slide to establish or disestablish communication with said source, and i. check valves communicating each side of the metering piston with each chamber, j. the construction and arrangement being such that during movement of the main piston toward a cylinder end, the metering piston moves in the opposite direction a predetermined distance, depending upon the position of its adjustable abutment and returns a portion of the additive to its source until it covers one of said ports, further relative movement between the main piston and metering piston moving the latter a predetermined distance beyond the covered port and delivering a metered quantity of the additive through one of the check valves and into one of said chambers, whereby mixing occurs during filling of said one of the chambers. 